Google Inc. made its name in Internet search and its money in advertising. What's with the cars?

The Silicon Valley giant has a secretive research and development wing called Google X, where it invests time and money on what it calls "moon shots."

Several years ago, Google started testing Toyota Priuses and then Lexus SUVs that it outfitted with an array of cameras and sensors, and heavy computing power.

So far, drivers have been behind the wheel for all 700,000 miles the cars have driven on public roads and been ready to take control if the electronics fail.

A NEW PROTOTYPE

Google noticed that employees who used the Lexuses would relax so much that they might not be ready to take over in an emergency. So the company set about developing a car that will not need a driver.

The prototype has two seats, a top speed of 25 mph and would be powered by electricity. There is no steering wheel or brake and gas pedals.

WHAT'S NEXT?

Google plans to test the car on closed courses this summer and then on public roads later this year. Once the company feels the car is safe enough, it wants to provide 100 prototypes to select members of the public.

Before the public can use truly driverless cars, however, California regulators need to finalize new rules allowing their operation. That process is due to be completed in the summer of 2015.